Field of Art
The present invention relates to a process monitoring system, apparatus, and method.
The present application claims priority based on Japanese patent application No. 2012-123948, filed on May 31, 2012, the content of which is incorporated herein by reference.
Background Art
As will be made clear by citing patents, patent applications, patent publications, scientific references, and the like, the content thereof is incorporated herein for the purpose of better describing the prior art relative to the present.
Conventionally, in plants, factories, and the like, a process monitoring system is implemented for monitoring various state quantities (for example, pressure, temperature, and flow amount) in an industrial process. A high level of automated operation is achieved, based on the monitoring results of the process monitoring system. This process monitoring system is generally constituted by on-site devices (measuring instruments and actuators) known as field devices, a controller that controls them, and a process monitoring apparatus that monitors state quantities.
The above-noted process monitoring apparatus collects measurement results (information indicating various state quantities) of the field devices obtained by the controller. The process monitoring apparatus then displays a graph (trend graph) indicating the current values and time variations of the state quantities measured by one or more specific field device. The process monitoring apparatus, in addition to the current values and trend graphs of state quantities, displays thresholds (upper and lower thresholds) with respect to the state quantities. The process monitoring apparatus also generates an alarm to notify of an abnormality when a state quantity exceeds a threshold.
Japanese Patent No. 4483111 and Japanese Unexamined Patent Application, First Publication No. H1-287419 disclose conventional process monitoring apparatuses to monitor a process. Specifically, Japanese Patent No. 4483111 discloses a process monitoring apparatuses that monitors a trend of gradual state variation in a plant by performing statistical processing with respect to time-sequence process data. Japanese Unexamined Patent Application, First Publication No. H1-287419 discloses a process monitoring apparatus that judges a variation trend of a process variable such as temperature, pressure, or flow amount (increasing trend, decreasing trend, oscillation, or the like) and displays the result of the judgment.
In recent years, efforts are being made to digitalize and impart intelligence to the above-described field devices, and it has become possible to collect a large amount of diverse information from field devices. With the ability to collect such a large amount of diverse information, because the amount of information required for process control becomes large, process control that is more accurate and more efficient than conventionally can be implemented. When the collected information becomes diverse and increases in quantity, however, along with an increase in the number of items to be monitored by plant operators, the scope of the monitoring broadens, as does the burden on operators.
To achieve process control that is both accurate and efficient, it is necessary to grasp fine variations in state quantities as quickly as possible. In addition, in order to improve the overall production efficiency in a plant or the like, it is insufficient to only control so as to achieve the optimum state in a part of the process steps, and it is necessary to implement high-level control that considers the states in upstream and downstream process steps relative to a particular process step. Conventionally, because an operator referred to the current values and trend graphs of state quantities to judge the state of the plant, unless the operator is sufficiently experienced, fine variations in state quantities are overlooked, making it difficult to achieve a highly efficient process.
If the art disclosed in the above-described Japanese Patent No. 4483111 and Japanese Unexamined Patent Application, First Publication No. H1-287419 is used, an operator not having a high level of experience can be aided to some extent. However, because an operator must make the ultimate judgment of the state of the plant, the achievement of a high-efficiency process still requires an operator with a high level of experience. Additionally, in a situation in which the information obtained from field devices becomes diverse and increases in quantity, the burden on even a highly experienced operator increases, bringing conventional monitoring methods close to their limit.